Big brains and Great Tits

For shame, dear reader — get your mind out of the gutter! Great Tits are adorable songbirds found commonly throughout Europe and Asia. And Christina Ricci (featured at left) is an actress whom I probably falsely assume has a relatively big brain behind her notoriously expansive forehead.

Rest assured, in this post I’ll be explaining how these concepts are related, and what the latest research has to say about why our brains are so much bigger than they need to be.

Now, about those tits:

Great Tits are gorgeous.

These birds are known to be very social, making songs and calls almost constantly as they communicate within their social groups.

Cuckoos are predominantly solitary birds that rarely get together in groups or pairs, which is one major difference between cuckoos and tits. The other notable difference is that tits have relatively bigger brains than cuckoos…is this a coincidence? Perhaps not, claims recent research out of Dublin, Ireland.

Big brains, big personalities!

It has long been known that the human brain is
larger than science would expect, given the brain-to-body size ratios of other primates. Some might say that the immensity of our brains is proportional to our species’ awesomeness. This might be true. However, a recent computer model suggests that our brains have grown over the course of evolution as we’ve evolved to be social creatures. This model makes sense when considering that bigger-brained primates tend to have larger social groups, and that the same pattern is observed in dolphins.

These researchers in Dublin set out to create a computer model that might help explain this “social brain” or “social intelligence” hypothesis. In short, the scientists started with a computer program representing 50 brains, each with just 3 to 6 neurons. Each brain would then challenge the other to the prisoner’s dilemma or the snowdrift game. The basic premise of both of these games is that each brain has only two options: cooperate and help the other brain get out of a troubling situation (like being in jail or being stuck in a snowdrift), or be more self-serving and do what’s best from a selfish perspective. The researchers even made it so that these virtual brains could learn to remember which brains had helped them in the past, and be more likely to help their previous accomplices in the future.

After 50,000 simulated generations of letting these brains interact, asexually reproduce, and randomly undergo mutations in brain structure or function, the findings clearly showed that increased cooperation led to better-performing brains with greater numbers of neurons. Of course, our brains, and those of primates and dolphins, have infinitely more choices to make than the ones in the computer program had, and we have way more than 3 to 6 neurons (try 80 to 120 billion). But still. This is cool because it’s an attempt to use more than just strict biology to explain something physiologically unexpected — namely, why our brains are so huge. This work comes on the heels of other recentpublications that similarly suggest a relationship between social network size and brain size.

And don’t think I’ve forgotten Christina Ricci. Just for funsies, let’s assume forehead size positively correlates with brain size. Here’s a collection of famous people who are either complete social butterflies or total loners, as determined purely by their forehead size.